AZ-700 Question 165
Single answerYour organization hosts a public-facing web application distributed across three Azure Availability Zones. You must use a single front-end IP address, preserve the original client IP address for logging on each VM, configure inbound NAT rules to allow direct RDP connections for troubleshooting, and collect detailed load-balancing metrics and logs. Which Azure Load Balancer configuration best meets these requirements?
- A
A Basic Load Balancer with a single backend pool and default distribution settings
- B
A Standard Load Balancer with zone redundancy, inbound NAT rules, and source IP�based session persistence
- C
An Application Gateway with a WAF tier and end-to-end TLS encryption
- D
An Azure Traffic Manager profile for DNS-based global load balancing
Show answer and explanation
Correct answer: B
Explanation
Azure Standard Load Balancer is the recommended choice for scenarios requiring a single front-end IP address, zone redundancy (for distributing traffic across multiple Availability Zones), preservation of client IP addresses, and inbound NAT rules (e.g., for RDP or SSH). Basic Load Balancer does not provide the advanced monitoring and zone redundancy needed. Application Gateway operates at Layer 7 and focuses on HTTP/HTTPS load balancing rather than providing simple NAT rules. Traffic Manager is a DNS-based solution for global distribution, not a direct load-balancing mechanism at the network layer. For further reference, see Microsoft Docs: 'Load Balancer SKU comparison' (https://learn.microsoft.com/azure/load-balancer/skus).
- A. Incorrect.
Option 1 is incorrect because the Basic Load Balancer lacks critical capabilities such as zone redundancy, advanced metrics, and selective inbound NAT rules needed for direct RDP access across multiple Availability Zones. Basic Load Balancer also offers limited logging and debugging features compared to Standard.
- B. Correct.
Option 2 is correct. A Standard Load Balancer supports zone redundancy for high availability across Availability Zones, supports preserving original client IPs, and allows inbound NAT rule configurations for direct RDP connections. It also offers advanced diagnostic metrics and logging, which fulfill the performance monitoring requirement.
- C. Incorrect.
Option 3 is incorrect for this scenario because Application Gateway is generally used for Layer 7 routing features (e.g., HTTP-based routing, WAF). While it does provide TLS termination and advanced routing, it does not offer the straightforward inbound NAT rules needed for RDP to specific VMs in a backend pool. It also does not typically replace the need for direct L4 load balancing with source IP preservation.
- D. Incorrect.
Option 4 is incorrect because Azure Traffic Manager is a DNS-based global load balancing solution that works at the DNS level. It does not provide direct NAT rules or preserve original client IP information for individual VM connections. It is designed to route users to the closest or healthiest endpoint globally rather than provide per-connection load balancing at Layer 4.